Various downhole elements used in a well have sections with ends that join together by threaded connections. In some applications, a power tong assembly is used to make up or break out the threaded connections for such elements. For example, a tubing tong is used to make up or break out the threaded connections between tubulars, such as drill pipe, tubing, casing, and the like. The tubing tong grips the external cylindrical surface of a tubular and then rotates the tubular while the other tubular to which it is connected is held stationary or rotated in the opposite direction. One particular example of a tubing tong is disclosed in US Pat. Pub. No. 2010/0083796, which is assigned to the Assignee of the present disclosure and which is incorporated herein by reference in its entirety.
Because the tubing tong grips the cylindrical surface of the tubular, the surfaces of its jaws have teeth that need to be preloaded to engage the tubular. Yet, the cylindrical surface of the tubular is essentially uniform so that closing the tong's jaws against the tubular simply involves mating a cylindrical grip surface against a uniform cylinder.
Other than tubulars, sucker rods are also used in wells and have sections with ends that join together by threaded connections. Sucker rods and their threaded connections are fundamentally different from tubulars. Notably, sucker rods are considerably smaller than the much wider tubulars. In addition, sucker rods have squares or drive heads with four flats that are used for rotating the sucker rods when making or breaking a threaded connection. These flats have square edges, which can become worn with use and can complicate the gripping of the flats.
Moreover, the threaded connection for sucker rods involves affixing a male end of one sucker rod to a male end of another sucker rod using an internally threaded connector. The squares on both sucker rods must be held to make or break the connection, and these squares can have any orientation relative to one another. By contrast, a typical tubular connection mates a male end of one tubular directly to a female end of another tubular, and both tubulars have cylindrical surfaces without any difference in alignment.
Because sucker rods and their threaded connections are fundamentally different from tubulars, a hydraulic rod tong is used to make up or break out the threaded connections between sucker rods. A typical hydraulic rod tong 10 of the prior art is shown in FIGS. 1A-1B. The rod tong 10 has a frame 20 supported by a hanger and suspension assembly 25. The frame 20 houses an outer ring gear 40 that couples by internal gearing 32 to a hydraulic motor 30 and valve components mounted on the frame 20. The other end of the frame 20 has a mouth 22 and an opening 24 that expose the outer ring gear 40. The mouth 22 can have gates 23 and can be sized for passage of sucker rod components (not shown).
An inner ring 50 fits in the outer ring gear 40 and has a pair of jaws 55a-b for gripping rod elements. FIGS. 2A-2B show components of this inner ring 50 in isolated detail. A body 52 holds the jaws 55a-b therein on hinge pins 54. Springs 56 can bias the jaws 55a-b in the body 52. When this inner ring 50 fits in the outer ring gear 40 as shown in FIGS. 1A-1B, opposing rollers (not shown) on the outer ring gear 40 engage the jaws 55a-b and can pivot them inward to engage rod elements.
As noted previously, the hydraulic rod tong 10 can be used to make up or break out connections between sucker rods. In FIG. 1B, for example, the rod tong 10 is shown relative to a connection between a first sucker rod R-1, a coupling C, and a second sucker rod R-2. Before fitting the rod tong 10 onto the rod components, operators first install the inner ring 50 in the frame 20 and rotate the gear 40 and ring 50 to an “open” position so the rod components can pass through the mouth 22 of the frame 20 to the ring's jaws 55a-b. 
Observing the bottom square on the lower sucker rod R-2, operators guide the rod tong 10 onto the lower sucker rod R-2 so that a back-up wrench 26 slides onto the flats F of the bottom square. With the rod tong 10 pulled forward, the jaws 55a-b inside the inner ring 50 automatically engage flats F of the upper sucker rod R-1 above the coupling C. Operators then use a control arm 28 to activate the motor 30, and the frame's internal gearing 32 rotates the outer ring gear 40. Engaged by the gear's rollers, the jaws 55a-b of the inner ring 50 then grip flats F of the upper sucker rod R-1 disposed therein. The backup wrench 26 prevents rotation of the lower sucker rod R-2, while rotating of the jaws 55a-b of the inner ring 50 tighten or loosen the upper sucker rod R-1 and the coupling C relative to the lower sucker rod R-2.
Making and breaking the connection between sucker rods R-1, R-2 requires the jaws 55a-b to have a proper orientation in the rod tong 10. In current rod tongs, the inner ring 50 has to be flipped over manually to change between make and break orientations. For example, FIGS. 3A-3B show the inner ring 50 and rod tong 10 set for making up a rod connection, while FIGS. 4A-4B show the inner ring 50 and rod tong 10 set for breaking out a rod connection.
To make up a rod connection, for example, operators first manually make-up the coupling C to a hand tight position (See FIG. 1C) on the sucker rods R-1, R-2. Operators then manually back off the coupling C approximately four turns. Operators set the inner ring 50 in the make orientation in the frame 20 and position the rod tong 10 in place on the rod connection as described previously. The jaws 55a-b engage the flats F on the upper rod R-1, and operators activate the throttle handle 28. The outer ring gear 40 and other components in the frame 20 rotate the inner ring 50 and tighten the connection between the rods R-1, R-2 and coupling C. When done, operators remove the tong 10 to make up the next connection on a rod string.
The rod string can be deployed and used downhole according to its purposes, or operators may pull and rerun the sucker rods depending on the implementation. Either way, operators will need to break out the various rod connections along the rod sting. To do this, operators need to remove the inner ring 50 and flip its orientation in the rod tong 10 to set it for breaking out rod connections.
To remove the inner ring 50, operators align the gear 40 and ring 50 as needed in the frame 20. At this point, operators disconnect the hydraulic power to the rod tong 10. With power disconnected, operators remove the inner ring 50 using an inner ring safety tool (not shown). The tool fits down into the opening 24 and engages the inner ring 50 so operators can remove the ring 50 without having to reach inside the rod tong 10.
After removing the inner ring 50, operators detach the safety tool, turn the inner ring 50 over, and reattach the safety tool to the inner ring 50 in its reverse orientation. When components of the rod tong 10 are set, operators install the inner ring 50 with the safety tool. The opening of the outer gear 40 must point in the direction of “make” when installing the inner ring 50 for the make configuration. The opposite orientation is need for the break configuration. When in place, the inner ring 50 drops down over brake drum pins, and the ring's top surface extends below the top of the frame 20. Operators then pull back on the safety tool to remove it from the inner ring 50.
Although current rod tongs 10 may be effective, they have a number of disadvantages. As noted previously, operators may need to disconnect the hydraulic power from the rod tong 10 when making manual changes to the inner ring 50. Failure to disconnect hydraulic power can be detrimental, and the need to disconnect from the power causes time delays during operations. Additionally, the various manual steps required to change the operation of the rod tong 10 increase the complexity of the tong 10 and make operating it more difficult.
The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.